Transcriptional changes in Giardia during host-parasite interactions

► Extensive gene expression changes were identified in Giardia intestinalis trophozoites due to interaction with human intestinal epithelial cells. ► The most highly up-regulated genes encode oxygen defense proteins and several members of the high cysteine membrane protein (HCMp) and Gly-rich repeat (GRREAT) families. ► Putative small RNAs were up-regulated.